The present invention relates to laundry appliances, particularly clothes washing machines. More particularly, the present invention relates to a device and method for optimizing the rotational speed of a washing machine tub during the spin cycle so as to minimize washing machine vibration.
A tuned vibration absorber mounted to a clothes washer has been found to effectively reduce machine vibration. The vibration absorber is tuned to reduce machine vibration when the tub is rotated over a range of speeds and is most effective when it vibrates out of phase with the vibration of the washing machine. Such a vibration absorber is described in applicant's co-pending application Ser. No. 08/996,755, filed Dec. 23, 1997.
One difficulty with a vibration absorption system is that the tuned frequency of the absorber is dependent upon the mass attached to the absorber, the spring rate of the springs, the amount of clothes in the tub of the washing machine, floor conditions, and other installation conditions. Consequently, the optimum operational rotational speed for the tub varies from machine to machine, installation to installation and cycle to cycle. Thus, it is not sufficient to preset the controls of the washing machine to spin the tub at a certain rotational speed. For these reasons, there is a need for a device and method of determining the optimum rotational speed of the tub during each spin cycle to best utilize the vibration absorber and minimize machine vibration.
A general object of the present invention is the provision of an improved automatic washing machine.
A further object of the present invention is the provision of an automatic washing machine which determines the optimum rotational speed for the tub during each spin cycle.
A further object of the present invention is the provision of a method for determining the optimum rotational speed for the tub during each spin cycle.
A still further object of the present invention is the provision of a method for quickly determining the optimum rotational speed of the tub to minimize machine vibration.
These as well as other objects, features and advantages of the present invention will become apparent from the following specification and claims.